1; This test is attempting to detect when we request forced re-alignment of the 2; stack to an alignment greater than would be available due to the ABI. We 3; arbitrarily force alignment up to 32-bytes for i386 hoping that this will 4; exceed any ABI provisions. 5; 6; RUN: llc < %s -mcpu=generic -stackrealign -stack-alignment=32 | FileCheck %s 7 8target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128" 9target triple = "i386-unknown-linux-gnu" 10 11define i32 @f(i8* %p) nounwind { 12entry: 13 %0 = load i8, i8* %p 14 %conv = sext i8 %0 to i32 15 ret i32 %conv 16} 17 18define i64 @g(i32 %i) nounwind { 19; CHECK-LABEL: g: 20; CHECK: pushl %ebp 21; CHECK-NEXT: movl %esp, %ebp 22; CHECK-NEXT: pushl 23; CHECK-NEXT: pushl 24; CHECK-NEXT: andl $-32, %esp 25; CHECK-NEXT: subl $32, %esp 26; 27; Now setup the base pointer (%esi). 28; CHECK-NEXT: movl %esp, %esi 29; CHECK-NOT: {{[^ ,]*}}, %esp 30; 31; The next adjustment of the stack is due to the alloca. 32; CHECK: movl %{{...}}, %esp 33; CHECK-NOT: {{[^ ,]*}}, %esp 34; 35; Next we set up the memset call. 36; CHECK: subl $20, %esp 37; CHECK-NOT: {{[^ ,]*}}, %esp 38; CHECK: pushl 39; CHECK: pushl 40; CHECK: pushl 41; CHECK: calll memset 42; 43; Deallocating 32 bytes of outgoing call frame for memset and 44; allocating 28 bytes for calling f yields a 4-byte adjustment: 45; CHECK-NEXT: addl $4, %esp 46; CHECK-NOT: {{[^ ,]*}}, %esp 47; 48; And move on to call 'f', and then restore the stack. 49; CHECK: pushl 50; CHECK-NOT: {{[^ ,]*}}, %esp 51; CHECK: calll f 52; CHECK-NEXT: addl $32, %esp 53; CHECK-NOT: {{[^ ,]*}}, %esp 54; 55; Restore %esp from %ebp (frame pointer) and subtract the size of 56; zone with callee-saved registers to pop them. 57; This is the state prior to stack realignment and the allocation of VLAs. 58; CHECK-NOT: popl 59; CHECK: leal -8(%ebp), %esp 60; CHECK-NEXT: popl 61; CHECK-NEXT: popl 62; CHECK-NEXT: popl %ebp 63; CHECK-NEXT: ret 64 65entry: 66 br label %if.then 67 68if.then: 69 %0 = alloca i8, i32 %i 70 call void @llvm.memset.p0i8.i32(i8* %0, i8 0, i32 %i, i32 1, i1 false) 71 %call = call i32 @f(i8* %0) 72 %conv = sext i32 %call to i64 73 ret i64 %conv 74} 75 76declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i32, i1) nounwind 77